On 14 Jan 2026, at 18:11, Florian Weimer <[email protected]> wrote:

> I think it's been previously observed that compression is not actually
> optional in practice, that is, the first answer record needs to start
> with 0xc0 0x0c.  It's not really related to ordering, but it fits
> the underlying theme of producing maximally compatible responses.

That theme sounds like a fun theme. However, the scope of this draft is 
narrower.

Our draft is aimed at addressing the specific problem we saw that broke things 
last week. We enlarged the scope slightly (we made a general rule for how to 
construct the answer section in general, not just when there is CNAME 
processing) but mainly we tried to choose a narrow scope and stick within it.

It feels a bit like if we started collecting all the nagging ambiguities in 
1034/1035 and put them all in the draft too we would have actually rewritten 
and modernised the whole DNS specification. History tells us that such a feat 
would be hard to pull off. In this draft we are not that ambitious, but this 
draft would still fit within such a theme. Future people who are more ambitious 
could include it together with all the other things, but in the mean time we 
have written down what we need to remember to avoid things breaking next time.

As an aside, I spent a few minutes looking for what prompted me to write that 
earlier draft in 2015, and I found

  https://mailarchive.ietf.org/arch/msg/dnsop/7KoE8Dr-SxuNToskxbvAwJ3BQLQ/

which reveals

  https://github.com/skynetservices/skydns/issues/217

which was also a glibc assumption about the ordering of RRs in an answer 
section, possibly the same assumption, I didn't look at the code.



Joe
_______________________________________________
DNSOP mailing list -- [email protected]
To unsubscribe send an email to [email protected]

Reply via email to